#!/usr/bin/python
# -*- coding: utf-8 -*-

# class Student:
#     def __init__(self,foo):
#         self.foo = foo
#     def __bar(self):
#         print(self.__foo)
#         print(__bar)

# def main():
#     stu = Student('hello')
#     stu.__bar()
#     print(stu.__foo)

# if __name__ == '__main__':
#     main()

# class Test:
#     def __init__(self, foo):
#         self.__foo = foo
#     def __bar(self):
#         print(self.__foo)
#         print('__bar')

# def main():
#     test = Test('hello')
#     test._Test__bar()
#     print(test._Test__foo)

# if __name__ == '__main__':
#     main()

# from time import sleep

# class Clock(object):
#     def __init__(self,hour=0,minute=0,second=0):
#         self._hour = hour
#         self._minute = minute
#         self._second = second
    
#     def run(self):
#         self._second += 1
#         if self._second == 60:
#             self._second = 0
#             self._minute += 1
#             if self._minute == 60:
#                 self._minute = 0
#                 self._hour += 1
#                 if self._hour == 24:
#                     self._hour = 0

#     def show(self):
#         return '%02d:%02d:%02d' % (self._hour,self._minute,self._second)

# def main():
#     clock = Clock(23,56,25)
#     while True:
#         print(clock.show())
#         sleep(1)
#         clock.run()

# if __name__ == '__main__':
#     main()



from math import sqrt

class Point(object):
    def __init__(self,x=0,y=0):
        self.x = x
        self.y = y

    def move_to(self,x,y):
        self.x = x
        self.y = y
    
    def move_by(self,dx,dy):
        self.x += dx
        self.y += dy
    
    def distance_to(self,other):
        dx = self.x - other.x
        dy = self.y - other.y
        return sqrt(dx ** 2 + dy ** 2)

    def __str__(self):
        return '(%s,%s)' % (str(self.x),str(self.y))

def main():
    p1 = Point(3,5)
    p2 = Point()
    print(p1)
    print(p2)
    p2.move_by(-1,2)
    print(p2)
    print(p1.distance_to(p2))

if __name__ == '__main__':
    main()